zic
Compile timezone data files
TLDR
SYNOPSIS
zic [OPTIONS] [FILE...]
DESCRIPTION
zic is the timezone compiler. It reads text files describing timezone rules (zone names, UTC offsets, daylight saving transitions) and produces binary TZif (Time Zone Information Format) files used by the C library's localtime() and related functions.Input files use a specific format with Rule, Zone, and Link lines that define timezone transitions. The compiled binary files are typically installed in /usr/share/zoneinfo/. The zic compiler is normally run as part of the tzdata package installation.
PARAMETERS
-d DIRECTORY
Output directory for compiled TZif files (default: system timezone directory).-l timezone
Use the given timezone as the local time, creating a localtime link.-p timezone
Use timezone's rules for POSIX-style TZ strings that lack transition rules.-L leapsecondfile
Read leap second information from the specified file.-v
Report warnings about the input data, including years outside the representable range.-b (slim|fat)
Output backward-compatibility data. "fat" generates extra entries for older software. "slim" keeps files small (default).-r @lo/@hi
Limit output to timestamps in the given range.-D
Do not create ancestor directories of output files.-m mode
Set file permissions on created TZif files.--version
Output version information and exit.
CAVEATS
Requires properly formatted timezone source files. Typically run as root when writing to system directories. Incorrect data can break time handling system-wide. The -y option for year type commands is obsolete and no longer supported in modern versions.
